Cooling system for electrical apparatus



Aug. 24, 1926.

l. W. FISK COOLING SYSTEM FOR ELECTRICAL APPARATUS Filed Sept. 21. 192;

Patented Aug. 24, 1926.

UNITED STATES IRA W. FISK, OF MDRGANTOWN, \VEST VIRGINIA.

COOLING SYSTEM' FOR ELECTRICAL APPARATUS.

Application filed September 21, 1923. Serial No. 664,127.

The present invention relates to electrical apparatus, and more particularly to alternating current transformers.

Alternating current transformers are frequently disposed in metal tanks containing oil or other suitable insulating fluid in. which they are immersed. During the operation of oil-immersed transformers, large quantities of heat are generated in their core members and coils, and in order to reduce the temperature of these parts, where forced circulation of the cooling fluid is not employed, relatively large tanks are used. The tank effectually reduces the temperature of the oil or other insulating fluid in the immediate vicinity of the walls of the tank, but, by reason of the poor heat conductivity of the fluid and also its inertia, the temperature of the active parts of the transformer is usually considerably higher than the average temperature of the surrounding cooling fluid.

It has heretofore been proposed to overcome these difficulties by providing means for producing a forced circulation of the cooling fluid. Such means, however, have usually been complicated and expensive and have usually involved the use of an external cooling medium and external equipment.

By the present invention, I have provided means for producing a forced circulation of the cooling fluid which is extremely simple in construction, may be entirely contained within the tank, and does not involve the use of any external cooling medium or equipment, but which is adapted to effect a quick removal of the cooling fluid from points of maximum temperature therein and the distribution of the hot fluid to the coolest portions of the walls of the tank.

In the accompanying drawings, there is shown for purposes of illustration only, one embodiment of the present invention, it being understood that the drawings do not define the limits of my invention, as changes may be made in the construction and operation therein disclosed without departing from the spirit of the invention or scope of my broader claims.

In the drawings, the figure is a sectional elevation of a transformer embodying my invention.

The transformer illustrated comprises the usual iron core 2 surrounding coils 3 and 4. This transformer is immersed in a cooling fluid 5, which may be oil, contained in a metal tank 6.

Within the tank adjacent the top thereof is a trough 7. The trough 7 may he supported upon brackets 8 projecting from the walls of the tank 6.. This trough, as shoun, is provided at its inner edge with an upstanding flange 9. trough is preferably spaced a slight distance from the inner surface of the walls of the tank to provide a space 10 for the passage of fluid discharged into the trough.

Supported upon a shelf 11 projecting in wardly from the walls of the tank just below the trough 7 and above the level of the cooling fluid in the tank, is a pump 12 driven by a small electric motor 13 also supported upon said shelf. A pipe 14: extends from said pump over the transformer and has vertical branch pipes 15 extending downwardly into the space between the'coils 3 and 4. A discharge pipe 16 extends from the pump 12 and has its discharge end arranged over the trough 7 The motor 13 may be of any suitable type, but is preferably so designed and electrically connected that it will start operating at a predetermined transformer current. While the motor is shown as located within the tank above the cooling fluid, it will be understood that it may, if desired, be located out side the tank.

It will be seen that the branch pipes 15 lead directly to points in the cooling fluid where the latter is at approximately the highest temperature. In operation, the pump 12 is adapted to rapidly withdraw the hot fluid from these points of approximately maximum ten'iperature and discharge it into the trough 7. The latter is constructed and arranged to deliver and distribute this hot fluid to the inner surface of the walls of the tank near the top of the latter. The hot fluid in running down the walls of the tank back into the main body of fluid has its temperature rapidly reduced.

The advantages of the present invention will be apparent to those skilled in the art. It enables a rapid circulation of the insulating fluid and a quick removal of the hottest portions thereof and the distribution of the same to the walls of the tank. The structure is extremely simple, may be entirely contained within the tank, requires no external cooling agent or equipment, and may in many cases be applied to existing transformers. All of these features render my invention important and desirable.

The outer edge of the I claim: 1. The combination with a tank, an elecrical transformer within said tank. comprisng a core and primary and secondar coils cal flange at its inner edge. a pump s portcd in the tank. a 'sch: e 3211K leading from the pump to said 'tlOl' f'il. or d z i intake pipe leading from the pump and having aplurality of launches exten ing; between said coils substantiall as ibezl.

2. The combination with a tanl-I an ele trical transl' ormcr within said tanl: coinrising a core and primary and secondar coils and a cool n fluid in said tank in which the trans't'ornier immersed, 0? means Jr producing a forced circulation of a lluid conthe cooling: fluid comprisii d between saul duit extending into said ll coils and means for with-:lra ing fluid from between the coils through said conduit and discharging the withdrawn 'zluid onto the inner surface of the walls of the tanl: adjacent the top thereofl substantially as described.

3. An electrical transformer comprising; a fluid container, transformer coils submerged in the fluid, a fluid conduit within the container and tern'iinating between windings of the transformer and means for drawing fluid through the conduit from lie-- tween the windings.

it. An electrical transformer comprising a "luid container, transformer coils submerged 1 le iuid, a tluid conduit within the conner and terminating between windings of the transformer, means for drmring fluid through the conduit from between the windiugs and a discharge trough adapted to re- (QIYG such fluid,- the trough being s 'iaied a siig 'ht distance from the walls of the coutainer to permit the flow of fluid over the i f walis oi the container substantially as ('iescribed.

electrical transtormer comprising a fluid container, transformer coils submerged in the fluid, a plurality of fluid condui wit 17in the eoi'itainer and terminating at difterent points between windings ot the trans tormer, a common. suction line connected t; of such conduits and a suction pump tr r swine; fluid from between windings 01 the. tramformer through said conduits. In testimony whereot I have hereunto set nv hand.

IRA V. FIS-K. 

